04-12-2022 07:07 PM
Hi Experts,
We have scenario where we have a point to point BGP configured between them.
Router A >> Tunnel 10 >> 10.50.0.1 255.255.254.0 (Subnet mask /20)
Router B >> Tunnel 10 >> 10.50.0.11 255.255.240.0 (Subnet mask /23)
The BGP connection is flapping every couple of hours/days etc.
Do you see any issue by any chance if the connection is flapping due to mismatch in the subnet mask?
Regards,
Dayesh
04-12-2022 07:37 PM
Hello
Do you have any L2/L3 issues that can be causing connectivity loss between source/destination of the bgp tunnels?
Can you post the configuration for the tunnels and bgp stanza
sh run int tun x
sh run | sec router
sh ip route static
sh ip interface br
sh ip bgp sum
sh ip bgp neighbors x.x.xx | in state
04-12-2022 11:47 PM
The BGP connection is flapping every couple of hours/days etc.
what is the logs you see on the device ? any interface up and down?
what % of usage that time on the interface?
what % CPU that time when it flaps?
what kind of links between this device to establish BGP?
is the BGP running over the tunnel, is the tunnel interface is the stable?
04-13-2022 09:43 AM
Hi @Dayesh Shetty ,
A very common cause for BGP session flapping is a mismatch path MTU between the two neighbors. Please refer to the following document to find out how to troubleshoot it.
Regards,
04-13-2022 03:31 PM
hi,
for the problem you need to get debug, you need to get interface and bgp debug !
the problem may be mtu or L1 level, cable signal or gbic sfp problem
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